In a wireless system (wireless communication system) having a plurality of operation channel candidates, the first procedure for connection is searching for a surrounding wireless terminal. When the search is performed without recognizing the mutual existence, each wireless terminal sequentially switches wireless channels, and further switches the functions of an active search side (or an announce side) and a waiting side temporally, as a normal searching procedure.
Such procedure secures mutual discovery at any point of time. However, unless a wireless channel (social channel for a search in the case of Wi-Fi Direct, for example) is provided at the same time between wireless terminals, the discovery is not possible in general. Thus, it may take long time to discover each other, depending on timing.
There have existed problems of deterioration of user operability and increase of power consumption due to prolongation of time for discovery. Moreover, when a plurality of candidates for a wireless system exist and they cannot be used at the same time, the combination is further increased, which prolongs time for discovery.
Conventionally, there is proposed a method of securing discovery by only searching for one wireless channel using one wireless channel preliminarily shared between terminals by any method. Note that in this case, there is no need to necessarily distinguish an active search state (or an announce state) and a waiting state because it is guaranteed that the wireless channel is provided and not shifted.
For example, Patent Literature 1 discloses the technology in which a wireless terminal having two wireless interfaces for wide-range wireless communication and narrow-range wireless communication preliminarily notifies, prior to neighborhood search in narrow-range wireless, a search target terminal of scan information such as a wireless channel, a search interval, and search start time to share it using wide-range wireless via a base station, so as to make a scan more efficient.
Moreover, Patent Literature 2, for example, discloses the technology in which a base station generates control information related to a search (channel, network ID, scan parameter, timing synchronization information) and notifies each terminal of the control information so as to make a scan more efficient.